Rose hip Extract Rosa canina Ascorbic Acid Vitamin C Who is this for? Uses Because fresh rose hips contain significant amounts of vitamin C, which is also known as ascorbic acid, they have been promoted for the prevention and treatment of the common cold. While no scientific evidence supports the theory that large doses of vitamin C can increase the body's resistance to colds or any other conditions, their high content of vitamin C and other nutrients such as folate makes rose hips a common ingredient in multiple vitamin products. The amount of nutrients in rose hips depends on the species of rose and on the growing conditions. In addition, their vitamin C content decreases with drying, processing, and storage; therefore, commercially available "natural" vitamins containing rose hips frequently also include vitamin C from synthetic sources. Some recent evidence from animal studies suggests that an extract of rose hips may have a protective effect on stomach tissue. Extracts are concentrated liquid preparations usually made by soaking chopped or mashed plant parts in a liquid such as alcohol, and then straining out the solid parts. In one study involving laboratory rats, rose hip extract protected against all experimentally-induced stomach ulcers. More study is needed to prove or disprove this finding. Rose hips have been used in the past to treat diarrhea. They contain a small percentage of tannins, which provide mild astringent properties. An astringent shrinks and tightens the top layers of skin or mucous membranes, thereby reducing secretions, relieving irritation, and improving tissue firmness -- all actions that may help relieve diarrhea. Rose hips may also have mild diuretic effects, meaning that they may promote the loss of water from the body. This possible diuretic action is thought to result from pectin and small amounts of natural fruit acids contained in rose hips. Studies of laboratory animals, though, show that the diuretic action of rose hips is both minor and unpredictable. Prescription and non-prescription drugs are more effective and reliable as both antidiarrheals and diuretics.